Effect of pesticide spray volumes and doses on the production of marketable lemons in Tucumán, Argentina

SALAS, H.; MANSILLA, C.; FIGUEROA, D.; CARRIZO, B.; ROJAS, A.; CAMPOS, A.; GOANE, L.

Valencia

Congreso; XII International Citrus Congress; 2012

International Citrus Society

Current management of lemon trees includes different pesticide volumes and doses. Field trials were conducted in lemon orchards located in two climatically and ecologically different regions throughout three years to evaluate the impact of three spray volumes (10000, 5000 and 2000 l/ha) and three doses of pesticides (high, medium and low) on lemon fruit health. The highest pesticide dose consisted of 15 kg/ha of a commercial product of copper hydroxide (53.8%), 100 l/ha of mineral oil and 2 l/ha of a commercial product of abamectin (1.8%); medium and lowest doses had the same components, but different quantities: the medium 7.5 kg, 50 l and 1 L, respectively, and the lowest 3 kg, 20 l and 0.4 l per hectare respectively. Trials were conducted in a randomized complete block design with four replicates. Healthy fruit percentage was estimated at harvest from approximately 2,000 fruits per plot. Damaged fruits were separately analyzed to discriminate the main cause for rejection: wind, pests or diseases. Independently of doses, healthy fruit proportion was significantly higher in plots sprayed with high and medium pesticide volume. Such treatments were more efficient for controlling pests (mealybugs, mites and thrips) mainly, although they resulted in a higher proportion of fruit damaged by wind. The study demonstrated that a reduction of pesticide spray volume (to 5000l/ha) and doses is possible without affecting fruit quality.